This is the final post in the Muscle Series. We've covered why GLP-1s cause muscle loss, how to get enough protein, and what resistance training looks like. Now — how to actually tell if what you're doing is working.
Most women track one number: the scale. That number tells you your total mass, but nothing about what that mass is made of. Two women can both be 150 pounds with completely different body compositions.
The body composition you end GLP-1 therapy with directly determines how well you'll maintain your results afterward. More muscle means a faster metabolism and better hunger regulation.
Signs That Muscle Loss Is Happening
- Losing more than 1–2 lbs per week consistently — faster loss is more likely to include muscle.
- Feeling weaker than expected — stairs, carrying groceries feel harder than your weight loss alone would explain.
- Lost weight but body feels softer, not firmer — fat percentage may have stayed similar even though total weight is down.
- Protein average consistently below 80g per day — below this threshold, muscle loss is significantly more likely.
- No resistance training in your routine — cardio alone doesn't protect muscle.
How to Actually Measure Body Composition
DEXA scan
The gold standard. Measures bone density, fat mass, and lean muscle mass separately. Takes 10 minutes, costs $40–$80 at many imaging centers. Worth doing at the start of treatment and at 3-month intervals.
Bioelectrical impedance (BIA)
The body composition scales at gyms. Less accurate than DEXA but far better than a regular scale. Measure at the same time of day, same hydration level, for comparisons to mean anything.
Strength as a proxy
If you're doing resistance training, track the weight you're using each session. If you're lifting the same or more over time, you're likely maintaining your muscle.
"The body composition you end GLP-1 therapy with directly determines how well you'll maintain your results in the years after."
What to Adjust If You're Losing Too Much Muscle
If you're consistently losing more than 2 lbs per week, discuss this with your prescribing physician — a dose adjustment may be appropriate. Track your protein honestly for 3–5 days. Add resistance training if you haven't started.
Activious members get access to our full guide on what to do when GLP-1 therapy ends — maintenance nutrition, metabolic protection, and how to build a plan before you stop the medication.
See what's included →